I can't seem to figure this out. I have a clunking/knocking noise coming from the transom. It is really obvious at idle. I am pretty sure it is not coming from the coupler and the u-joints were fine when I pulled the drive and merlin540 just put a gimbal bearing in it a few weeks ago. I appears it is coming from inside the bellows, but that doesn't make any sense to me. It's not like there are alot of parts in there. Allignment is dead on and the outdrive shaft is all the way into the coupler, as far as I can tell. At first I thought maybe the ujoints were getting bound up, maybe that is the case still.

Any ideas? It is not on a rythym, more inconsistent, like something is being knocked around. Pretty loud as well. Has me confused, any suggestions would be great. Not sure what brought it on, it has been doing it for a while, I just thought it was normal racket being made.

Thanks for any help or ideas...

Allan

Do you have the "Y" exhaust pipe that goes down to the through prop exhaust? If so, there are flappers inside the "Y" that can make alot of noise at idle.

Allan4,

What position was you drive in? I've noticed a "rattle" out of both of mine , if they're trimmed to the max. This is how I usually trailer it. If I start it in the driveway or even at the ramp without lowering them to a civilized level they'll do it. Lower them a bit and it stops. Replaced one drive last spring with a BRAND new one...that does the same thing

No, I go straight out the back...Gil's. It is more of a clunking sound. Like something is rattling around. I know the transom assembly makes some noise, but this seems excessive.

Thanks though....

Ohyeah, forgot to mention, 24 Outlaw, B1 1.50. Thanks

Mopower, the drive is within running tolerance. It is one the trailer right now, so I cannot drop it all the way down, but it is under the trailering level and at safe operating range. It's gotta be something simple like that.....just not that many parts back there. I think maybe the u-joints are bound up and shifting and hitting eachother or something, I just can't think of anything else.

Oh yeah, I have dual ram hydro assist on it, so it is not the drive shaking back and forth.....

Thanks guys....Allan

Sounds best to pull drive and recheck the u-joints. Then at least you can run motor on the hose w/o the drive on and either eliminate or blame the drive.

Yup....guess I was pretty stupid not to think of running the boat without the drive when the drive was off. Good idea,I guess that would be one way to check the coupler....hhmmmmmm, wish I would have thought of this a week ago.

Thanks, I'll try that and see what happens

Any other thoughts??

Are you sure it's not the flappers in the exhaust tips???
Some are counter weighted and silicone coated SS. When the silicone wears off, they can make a lot of racket. Just put your hand on the the exhaust hose at the tips and you'll be able to feel it.

Like giff said the internal exhaust flaps can make quite a racket. It is more noticable at idle because of the of the spaced exhaust pulse. However it is more of a clank than a knock. You still might want to look there first since it is easy to check.

I'm gonna say internal flappers also.